This file is from Wikimedia Commons and may be used by other projects.
The description on its file description page there is shown below.

Summary

DescriptionSemanticMediaWiki Logo.png

English: A 200px version of the new logo of Semantic MediaWiki, as introduced 31 Oct 2010. This file is uploaded here only to replace the very outdated previous image that was still used in Wikipedia. Further versions of this file can be found at http://semantic-mediawiki.org/wiki/SMW_logo.

attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.

This refers to the current version only. The original image had been created by Markus Krötzsch using Wikipedia artwork that is copyrighted by the Wikimedia Foundation and that could therefore not be released under this license.

Original upload log

The original description page was here. All following user names refer to en.wikipedia.